how to handle parse error for eval function in php

Question

I\'m trying to use the eval function for php. but I\'m stuck in handling the parse error. like considering if I have edge cases like 1.. or 1++ if gives me parse error:synta

Answer 1

$response = @eval($string);
if (error_get_last()){
    echo 'Show your custom error message';
    //Or you can 
    print_r(error_get_last());
}

Answer 2

From the manual

As of PHP 7, if there is a parse error in the evaluated code, eval() throws a ParseError exception. Before PHP 7, in this case eval() returned FALSE and execution of the following code continued normally. It is not possible to catch a parse error in eval() using set_error_handler().

Instead use this:

<?php

try {
    eval('will cause error');
} catch (ParseError $e) {
    echo 'Caught exception: '.$e->getMessage()."\n";
}

https://3v4l.org/1giOS

Answer 3

From the manual:

If there is a parse error in the evaluated code, eval() returns FALSE and execution of the following code continues normally. It is not possible to catch a parse error in eval() using set_error_handler().

But as you won't be calling eval on arbitrary code (right?), this shouldn't be a problem.